We have developed an unobtrusive eyedrop medication monitor that closely resembles a standard 30 cc eyedrop bottle and yet has the capacity to record electronically the date and time of each medication administration. Patients are not aware of the function of the monitor. Recent studies utilizing this device indicate that glaucoma patients have a high rate of defaulting from pilocarpine, timolol, and epinephrinedepivefrin treatment as expressed by missed doses, poor time spacing of doses and entire days without medication. To complement these studies we recently developed a pill medication monitor that works by the same principle as the eyedrop monitor. It is crucial to understand the relationship between compliance with medical treatment and prognosis in glaucoma. We will study the impact of the rate of compliance with antiglaucoma medication (miotics, topical beta adrenergic antagonists, epinephrine/dipivefrin and oral carbonic anhydrase inhibitors) on the prognosis of patients with primary open-angle glaucoma as determined by progressive optic nerve and visual field damage. Many clinicians are skeptical about whether intervention programs can improve compliance over the long term. We will test an exciting new intervention program to reduce defaulting by allowing patients to record their own medication behavior using the medication monitor. The patients will be told the purpose of the device and asked to monitor themselves. At each visit, the physician and the patient will review the compliance printouts for the period since the last examination. Many clinicians believe compliance with oral carbonic anhydrase inhibitors is poor because of drug-induced side effects. Using our newly developed pill monitor we will measure compliance with oral acetazolamide and methazolamide. We will determine which drug and which dosage schedule are associated with the highest rate of compliance. Many ophthalmologists have questioned whether some of the effect of laser trabeculoplasty on intraocular pressure is mediated by increased compliance. This question has bearing on the mechanism of action of laser treatment as well as the cause of early and late laser treatment failures. We will measure compliance with antiglaucoma medications pre- and post-laser trabeculoplasty.